I have not heard about the static coefficient of friction between concrete to concrete. But know the friction coefficient bet. rubber and concrete which is 1.0.
Extending the same logic and since the concrete is heavy the static coefficient of friction may be around 1.0.
Its very difficult to give even an approximate answer. It will have a bearing on the condition of two concrete blocks. It will be significantly different in both of the following conditions:-
1. between smooth concrete blocks (seperately cast)- 0.3 to 0.4
2. single casting of concrete block cracked into two parts 0.5 to 1.0.
Moreover present of moisture and presence of crushed material between the surfaces may bring down the friction factor dramatically. You have to be more specific about the conditions and then you can arrive at a more reasonable approximation.
Thanks for the good advice & tips dudes. We are down a tunnel at the moment so yes, moisture is a condition. The bits were cast separately. We'll go for the side of caution: 0.3 will do for now.
Flamby (or anyone else),
Any chance you can point to a reference for the use of 0.3 to 0.4 for seperately cast concrete? We're trying to verify that concrete traffic barriers can be used as ancorage points against a lateral load.
Thanks,
Jack
